Anode electrode for electron discharge device

ABSTRACT

An anode electrode for an electron discharge device is provided having inwardly projecting fin means to electrostatically extend the anode toward the grids. The fin means are arranged to provide dual paths of heat flow from the fins to both the flange portions and the sidewalls of the anode electrode.

O United States Patent 51 3,641,380 Stephens 1 Feb. 8, 1972 [54] ANODE ELECTRODE FOR ELECTRON 3,428,844 2/1969 Droppa ..3 1 3/39 DISCHARGE DEVICE 3,151,265 9/ 1964 Stephens... ..3 1 3/356 [72] Inventor: Joe F. Stephens, Owensboro, Ky. Primary Examiner-Roy Lake Assistant Examiner-Darwin R. Hostetter [73] Asslgnee' General Electric Company Attorney-Nathan J. Comfeld, John P. Taylor, Frank L. Ne'u- [22] Filed: Feb. 24, 1970 hauser, Oscar B. Waddell and Joseph B. Forman [21] Appl. No.: 13,576 p Y [571 ABSTRACT [52] US. Cl ..313/39, 313/46 An anode electrode for an electron discharge device is [51] Int. Cl. H011 19/36 vided having inwardly projecting fi means to electrostatically of ..3 1 40, extend the anode toward the The fin means are to provide dual paths of heat flow from the fins to both the [56] References Cited flange portions and the sidewalls of the anode electrode.

UNITED STATES PATENTS 5 Claims, 5 Drawing Figures 3,304,453 2/1967 Dlouhy ..313/40 4 PATENTEB FEB 8 I972 FIG.I.

T 00. i J

mvsmoh: JOE F. STEPHENS,

HS ATTOPNE ANODE ELECTRODE FOR ELECTRON DISCHARGE DEVICE CROSS-REFERENCE TO RELATED APPLICATIONS This application is related to application Ser. No. 13,564 filed on even date and assigned to the assignee of this application.

BACKGROUND OF THE INVENTION This invention relates to electron discharge devices more particularly to such devices .that are adapted for operation at relatively high power.

My previous US. Pat. No. 3,151,265 issued Sept. 29, 1964 and assigned to the assignee of this invention describes and claims an anode structure for a beam power tube. The claimed anode structure inhibits emanation of spurious oscillations or snivets which are more fully described therein whensuch a tube is used, for example, in the horizontal deflection circuitry of television receivers. Briefly the anode structure described therein extends the anode electrostatically toward the inner electrodes via an integral fin assembly.

While this construction successfully eliminated the electronic difficulties theretofore experienced, the construction resulted in a concentration of heat generated about the fin assembly, necessitating removal of the heat.

It has become the practice to construct such anode structures of laminated metals comprising a good head conducting core such as copper and outer facing layers comprising alurninized or alitized iron which is a good heat radiator but a poor heat conductor. Thus, particularly when using such laminated anode material, heat removal in the structure of the above referenced patent is somewhat limited by the structural shape of the integral fin wherein the conducting heat path is via a single path.

In recent years this'problem has been aggravated by higher plate power used to achieve greater deflection angles in television tubes due to the demand for flatter or narrower television sets.

It is therefore an object of the invention to provide an improved anode structure having means for more etficient removal heat from the fin assemblies. Other objects of the invention will be apparent from the description.

SUMMARY OF THE INVENTION Briefly considered, and in accordance with the invention, an anode is provided comprising first and second substantially channel-shaped members, each having a pair of sidewalls, an end wall, flange members on each of the sidewalls extending outwardly, and fin means projecting inwardly from each of the sidewalls to electrostatically extend the anode, each of the fin means comprising a dual member providing a first heat conducting path to the flange and a second heat conducting to the sidewall, and means for joining the channel-shaped members together.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partially cutaway isometric view of one embodiment of the invention.

FIG. 2 is a section view of FIG. 1 taken along lines II-Il.

FIG. 3 is a fragmentary view of a portion of FIG. 1.

FIG. 4 is a fragmentary isometric view of another embodiment of the invention.

FIG. 5 is a section of another embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, and particularly to FIGS. 1, 2, and 3 an anode 2 is shown having channel-shaped members 4 and 6. Members 4 and 6 are substantially mirror images of one another. They can be formed from a single sheet of stock with a single scam or, as illustrated, can be formed as two separate pieces and joined, for example, at 12 and 14. Member 4 comprises an end wall 16, sidewalls l8 and 20, and

LII

flange portions 22 and 24. In the illustrated embodiment, sidewalls l8 and 20 have outwardly extending sections 18c and 200, fonned by-bending a portion of the sidewalls, and second sections 18b and 20b, formed by bending a portion of sections 18c and 20c through a reverse angle so that sections 18b and 20b are approximately parallel to sidewalls l8 and 20.

In accordance with the invention, inwardly extending fin members 21 and 23 comprising dual wall members are provided on member 4. Fin 23 comprises a portion 240 of flange 24 and an inwardly extending portion 200 of sidewall 20. As best seen in FIGS. 1 and 3, portions 20a and 240 comprises a single integral sheet folded over against itself approximately 180.

It should be noted here that the foregoing description of member 4 also describes the mirror image channel member 6 as well. Thus, four fins are provided in the anode. Flanges 22 and 24 are shown spaced apart from corresponding flanges 32 and 34 on member 6 by respectivetapered end portions 25, 26, 27, and 28.

As stated above, the basic purpose of providing inwardly projecting 'fins on the anodes of beam power tubes is to correct or mitigate RF radiation by electrostatically extending the anode toward the interior electrodes. Resulting excessive heat generation must, as mentioned above, be reckoned with and thus the structure of the invention as described provides a dual heat path from each fin; i.e., a first path via portion 24a to flange 24 and a second path via portion 204 to sidewall 20.

However, the inhibition of secondary electron emission is also a design problem encountered when projections are extended from the anode. My invention, therefore, addresses itself to this problem as well as providing a type of serrated edges as best seen in FIGS. 1 and 3.

In the embodiment shown in FIGS. 1 and 3, the serrations provided to minimize the area available for secondary electron emission are formed by peeling back tabs alternately cut respectively out of portions 20a and 240. Thus tab 40 is cut out of portion 24a and, when peeled back, forms an extension of portion 20a. Tab 42, is contrast is cut out of portion 200 and, when peeled back, forms an extension of portion 24a. Small uncut areas 41 are provided between the tabs to maintain the integral fonn of a fin assembly and to provide mechanical stability. Thus, the edge surface presented to the electrons is only one layer thick and somewhat less in height than the total height of the fin. By alternating the tabs as described, however, the dual heat path structure is retained, i.e., tab 40 conducts heat away via portion 20a while tab 42 conducts heat away via portion 240. The alternation of the tabs is particularly important, it should be noted, when laminated anode material, such as previously described, is used to construct the anode. If all the tabs were formed, for example, from' portion 20a and thus formed extensions of portion 24a, very little heat would be conducted via portion 20a to sidewall 20 because the heat would not conduct across the abutting surfaces of portions 20a and 24a. By alternating the tabs, the heat is conducted via the inner heat conducting layer of the respective portions.

In FIG. 4, an alternated serrated edge is illustrated wherein a sawtooth-type effect has been attained by periodic removal of small amounts of both portion 20a and portion 24a as indicated at numerals 50, 52, and 54, Between these cutaways, uncut projections 41 retain the fin assembly in integral form.

FIG. 5 illustrates another alternate embodiment of the invention. In FIG. 5, wherein like numerals indicate the same structure and primed numbers indicate modifications, channel members 4' and 6' are illustrated as formed separately without flanges. A separate connecting member 36 comprises flanges 24' and 34' joined together by an end wall 26'. Connecting member 36 is joined to members 4 and 6, for example, by welding the respective fin portions 240' and 34a to corresponding fin portion 20a on channel members 4' and fin portion 50 on member 6'. Connecting member 38, which is identical to member 36' connects members 4 and 6' by attachment of fin portion 22a to fin portion 18a and fin portion 60 to fin portion 32a as illustrated. In this embodiment, the serration or tabs illustrated in either FIGS. 3 or 4 can be used as well.

Thus, my invention provides an anode structure having internal fins to electrostatically extend the anode toward the internal electrodes yet provides dual heat paths from each fin respectively toward the flanges of sidewalls of the anode to provide maximum dissipation of the localized heat generated at the fins. The invention further provides an anode structure wherein the emission of secondary electrons is mitigated by reduction of the total emission area of the fins. My invention can be practiced in a number of geometrical shapes and forms without departing from the spirit of the invention which is to be limited only by the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. An anode comprising first and second substantially channel-shaped members each comprising:

a. a pair of sidewalls and an end wall,

b. flange members on each of said sidewalls extending outwardly,

c. fin means projecting inwardly from each of said sidewalls to electrostatically extend the anode, each of said fin means comprising a dual member comprising a folded unitary layer providing a first heat conducting path to said flange and a second heat conducting path to said sidewall, said folded layer having cutaway portions adjacent to fold to expose both portions of the layer, and

d. means for securing said first and second channel-shaped members together. i

2. The anode of claim 1 wherein said sidewalls, flange members, and fin means comprise laminated metal comprising core material having good heat conducting properties and surface material having good heat radiating properties.

3. The anode of claim 2 wherein said cutaway portions are alternately cut from both of said unitary layer to expose said core material of both layer portions.

4. The anode of claim 1 wherein said means for securing said first and second channel members together include means for spacing apart adjacent flange members on said channel members to provide four spaced-apart fin means each having a direct heat-conducting path to a flange and a second direct heat-conducting path to a sidewall.

5. An anode for an electron discharge device comprising a cathode and at least one grid element, said anode having a plurality of fin means thereon projecting inwardly toward said grid and cathode to electrostatically extend said anode toward the grid and cathode each of said fins means comprising a unitary sheet of anode material having a fold therein to form a dual layered member and having cutaway portions adjacent said fold alternately cut from both layers to expose edges of both layers to provide a first heat conducting path through one layer to one portion of said anode and a second heat conducting path through the other layer to another portion of said anode. 

1. An anode comprising first and second substantially channelshaped members each comprising: a. a pair of sidewalls and an end wall, b. flange members on each of said sidewalls extending outwardly, c. fin means projecting inwardly from each of said sidewalls to electrostatically extend the anode, each of said fin means comprising a dual member comprising a folded unitary layer providing a first heat conducting path to said flange and a second heat conducting path to said sidewall, said folded layer having cutaway portions adjacent to fold to expose both portions of the layer, and d. means for securing said first and second channel-shaped members together.
 2. The anode of claim 1 wherein said sidewalls, flange members, and fin means comprise laminated metal comprising core material having good heat conducting properties and surface material having good heat radiating properties.
 3. The anode of claim 2 wherein said cutaway portions are alternately cut from both of said unitary layer to expose said core material of both layer portions.
 4. The anode of claim 1 wherein said means for securing said first and second channel members together include means for spacing apart adjacent flange members on said channel members to provide four spaced-apart fin means each having a direct heat-conducting path to a flange and a second direct heat-conducting path to a sidewall.
 5. An anode for an electron discharge device comprising a cathode and at least one grid element, said anode having a plurality of fin means thereon projecting inwardly toward said grid and cathode to electrostatically extend said anode toward the grid and cathode each of said fin means comprising a unitary sheet of anode material having a fold therein to form a dual layered member and having cutaway portions adjacent said fold alternately cut from both layers to expose edges of both layers to provide a first heat conducting path through one layer to one portion of said anode and a second heat conducting path through the other layer to another portion of said anode. 